Condensation products of an alkyl phenol with an aromatic dibasic acylating agent



Patented July 26, 1949 CONDENSATION PRODUCTS OF AN ALKYL PHENOL WITH AN AROMATIC DIBASIC ACYLATING AGENT Eugene Lieber, New York, N. Y., assiznor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application October 24, 19%, Serial No. 560,193

9 Claims. i

This invention relates to a novel type of chemical condensation product and to methods of preparing such products and using them for various purposes, more particularly as pour depressors in waxy lubricating oils.

One object of the present invention is to make wax modifiers especially useful as pour depressors in waxy lubricating oils from raw materials not heretofore known to be capable 'of being converted into pour depressors, namely, the class of lower alkylated phenols containing short chained alkyl groups, i. e.,less than a total of about 12 carbon atoms.

It is already known that pour depressors can be made by various condensation reactions involving the use of long chained aliphatic compounds, as for example, the condensation of chlorinated paraiiln wax with naphthalene; and it is also known that pour depressors can be made by acylation of alkylated phenols having long chained alkyl groups such as those derived from paraffin wax. However, it has generally been considered necessary by those skilled in the art when making pour depressors to always use at least one reactant having long chained aliphatic groups, and it was also usually considered desirable to have a plurality of such long chained aliphatic groups present for each aromatic molecule present. However, by means of the present invention a way has been discovered for obviating the necessity of either of those two factors, namely, the long chained aliphatic groups and the use of a plurality of such groups.

Broadly, this invention comprises the production of wax-modifying agents by chemically condensing an aliphatic-substituted hydroxy aromatic compound containing aliphatic groups having only less than 12 carbon atoms and containing as little as only one such group, with an acylating agent.

The aliphatic-substituted hydroxy aromatic compound to be used should preferably have the general formula Rum-43H, inwhich R represents an aliphatic group, preferably an alkyl group, having less than 12 carbon-atoms,.n is 1 ,to 4, preferably 1 to 2, and Ar is. an aromatic nucleus. If the acylating agent is aliphatic the number of carbon atoms in the phenolic B group should be about 1 to 5, there being a total of about i to 10 aliphatic carbon atoms in Rn:

whereas if the acylating agent is aromatic the.

number of carbon atoms in the phenolic B should be about 4 to 10, with a total of about i to 20 ali- Phatic carbon atoms in Rn.

The phenols and naphthols containing low molecular weight aliphatic substituents are typical members of this class of compounds. Some specific examples include the various amyl phenols such as para-tertiary amyl phenol, isobutyl phenol, n-butyl phenol, isopropyl phenol, npropyl phenol, cresols, di-butyl phenol, di-amyl phenol, sec. hexyl phenol, iso-octy1 (di-isohutyl) phenol, di-isooctyl phenol, etc., as well as monoamyl, alpha or beta-naphthol, butyl naphthols, propyl naphthols, etc. It should be understood that the alkyl groups can be located in various positions around the aromatic nucleus in respect to the hydroxyl group and that the alkyl groups may be straight chained or branched. Also, there can be two or more hydroxy groups and there can be two or more alkyl groups present, although the results are generally at least as good with only a single alkyl group, if not better, as compared with two or more alkyl groups.

Instead of the naphthalene nucleus other polynucleararomatic compounds may be used, such as suitable alkylated and hydroxy derivatives of anthracene, phenanthrene, diphenyl, etc.

Although there are some alkylated phenols on the market, 1. e.. commercial products, such as tertiary amyl phenol, petroleum phenols, etc., which are suitable for use according to the present invention, it is possible to start with an unalkylated phenol and treat it with a low molecular weight alkyl halide or an olefin in the presence of a Friedel-Crafts type catalyst, such as aluminum chloride, in order to' make the alkylated phenol, as for instance. by reacting ordinary phenol with amyl chloride in the presence of aluminum chloride to produce para-amyl phenol. The resulting reaction mass containing the amyl phenol can be used directly for the Present invention without preferably 2 to 10, or may have the general formula Ar(COOH) 2, where Ar represents an'aromatic nucleus such as the nucleus Calif-i, in phthalic acid or phthalic anhydride. The acylating agent is preferably used in the form of the acid halide or the acid anhydrlde. Specific examples of suitable aliphatic acylating agents are the acid chlorides or acid anhydrides of the following acids: oxalic. malonic, succinic, glutaric, adipic, pirnelic, suberic, and sebacic. Other aromatic acylating agents include: diphenic acid,

naphthalic acid, pyridine dicarboxylic acid, etc.

To effect the condensation of the alkylated hydroxy aromatic compound containing low molecular weight alkyl groups, with the acylating agent, according to the present invention, it is preferable to use a Friedel-Crafts catalyst, particularly aluminum chloride, although other Friedel-Crafts catalysts may be used, such as boron fluoride, zinc chloride, ferric chloride, titanium tetrachloride,"

boron trichloride and in some cases even anhydrous hydrogen fluoride.

The condensation is preferably carried out in the presence of inert solvents, such as a highly refined naphtha or kerosene, tetrachlor-ethane, carbon disulfide, etc., although if desired the use of the solvent may be dispensed with. The proportions in which the reactions should be used should usually be about /2 to 10; mols, preferably 1 to 5 mols, of the aliphatic-substituted hydroxy aromatic compound to 1 mol of the dibasicacid acylating agent. The amount of catalyst to be used should usually be about 0.2. to 3.0 mols, preferably 0.5 to 2.0 mols perimol of acylating agent. If a solvent is used, thevolume thereof should usually be about /2 to 1d, preferably .1 to 5, times the total volume of the reactants to catalyst. V

In carrying out the invention, the reaction temperature should be maintained between the approximate limits of room temperature and about 400 F., preferably between about 100 and 300 F. The preferred procedure is to add the catalyst to the reactants gradually at room temperature, and then to heat the reaction mass to the desired maximum temperature, maintain it there, such as by refluxing itfor the desired length of time, which would normally be between about minutes to 10 hours, preferably about /2 hour to 5 hours. The temperature and time should be adjusted to give the maximum yield of pour depressorhaving the desired pour depressing potency.

a After the reaction has been completed, the reaction mixture is cooled and preferably diluted with an inert diluent, such as a refined kerosene, then the catalystis hydrolyzed and neutralized by any of the known methods, such as by using a mixture of water and alcohol, or an aqueous solution of caustic soda, or even .plain water or plain alcohol. The whole mass is then allowed The condensation product of this invention is soluble in mineral lubricating oils and has a fairly high molecular weight, as it is substantially nonvolatile at temperatures below about 600 F. It usually has a color ranging from a green to a brown and, has,a physical consistency or texture ranging from a viscous oil to a resin, in some cases to settle and the aqueous catalyst layer is drawn oil. The upper or kerosene layercontaining the having an intermediate gummy consistency.

Although the chemical structure of the products of this invention has not been determined' with certainty, it is believed that they may be represented by a linear-chained structure having alternate aromatic nuclei, in case the acylating agent used was an aliphatic dibasic acid, or a linear type chain built up of different types of aromatic nuclei, one type of which was derived from the alkylated hydroxy aromatic compounds and the other of which was derived from an aromatic dibasic acid. In any case, however, the linear chain type structure also possesses some free aliphatic groups which originated as substituents on the hydroxy aromatic compounds used as raw material. The success of this invention may in part be due to the better solubility of short aliphatic groups, having less than 12 carbon atoms, in waxy mineral oils, as compared to long straight chain parafiinic groups such as that of parafiin wax.

The product of this invention has the property of modifying the crystal structure of waxes such as paraffin wax present when added to compositions containing the same. For instance, when about .05- 0.0%, preferably 02-50%, of this wax modifier is added to a waxyv lubricating oil such as a Pennsylvania type lubricating oil having a relatively high pour point, the resultant blend will have a substantially lower pour point; in other words, this wax modifier is an effective pour depressor for waxy oil. A small amount of this wax modifier is also useful as a dewaxing aid for removing wax from mineral lubricating oils of undesirably high wax content. In similarly small amounts,.this wax modifier may also-be incorporated into paraffin wax or compositions containing the same to be used for various purposes such as for coating or impregnating paper, etc., or for making various molded products.

For the sake of illustration, but without limiting the invention to the particular materials used, the following experimental data are given: H

34 grams of sebacic acid were treated with 25 grams of phosphorous trichloride on the water bath. The resulting sebacyl 'chloride was decanted from the phosphorous acid into a solution comprising grams of tert-amyl-phenol dissolved in 200 cc. of tetrachlorethane used as selvent; 55 grams of anhydrous AlCla were then slowly added to the reaction mixture. After the addition ofthe AlCls, the reaction mixture was refluxed under a return condenser for 30 minutes. At the end of this time the reaction mixture was cooled, diluted with kerosene, and the AlQla destroyed by the additien of water. After settling, the kerosene extract, was distilled with fire and steam to 600 F., in order to remove solvent and low-boiling products. A bottoms residue comprising 64 grams of a brown viscous gummy substance was obtained as product.

When 2% of this condensation product was added to a waxy oil, the pourpoint ofwhich was +30 F., the pour point was found to be 5 F.

A number of other tests were made using sebacic acid chloride and more or less the same general procedure as; that described above, except that several different alkylated phenols were used and various proportions of both reactants, and the stituted aromatic nucleus with 1 mol of an acylating agent having the general formula Ar (COX) 2,

Table Dibesio Acid Alkylated Phenol Aiming Solvent Product Cet. a Test c 'lcmp., Time, Gu f POL'll' Point Name Gm. Name Gm. Name cc. Egg 53, 232, Appearance 1 t.-omylphenol.... 120 Beanie 34 55 01111014... 200 Reflux, it 64 Brownviscgummy.

e 2 .-do 00 --.do--.- 34 55 -..--do 200 do. is 85 Do. 3 Di-amylphenol.. 94 ...do.. 40 64 ....-do..-. 200 0.- 3 127 Green visc. oil. 4 do 47 do i0 54 -...do. 200 ..do 3 56 l() Darkbrownresin.

1 Blend in a waxy lubricating oil base stock have a pour point of +30 F.

It is noted that in all four of the above tests 20 in which Ar represents an aromaticnucleus and the condensation product produced a 35 to 50 F. lowering of the original pour point (+30 F.)

of a waxy lubricatlngoil base stock, when added Test 5 150 grams of diisobutylphenol were dissolved in 200 cc. of tetrachlorethane as solvent and 50 grams of aluminum chloride added. 50 grams of phthalyl chloride are added to the reaction mixture with stirring over a period of about 30 minutes. After the addition of the phthalyl chloride the reaction temperature wasincreased to 225 F. and maintained thereat for 3 hours.

' After cooling, the reaction mixture was diluted with a further quantity of solvent and the aluminum chloride destroyed by a mixture of alcohol and water. After settling and removing the sludge layer the product was recovered by fire and steam distillation to 600 F. inorder to remove solvent and low boiling products. 64 grams of a dark brittle resin was obtained as product.

The pour depressant potency of the condensation product prepared as described above was tested by blending to 5% concentration in a waxy mineral oil having an initial pour point of +30 F. and testing the resulting pour point of the blend by the standard ASTM procedure. A pour point of --10 F. was found.

This application is a continuation-in-part of copending application Serial No. 372,195, filed December 28, 1940, now Patent 2,366,735.

It is not intended that this invention be lim ited to any of the specific examples which were given merely for the sake of illustration nor to any theory as to the mechanism of the operation of the invention, but only by the appended claims in which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

It is claimed:

1. A Friedel-Crafts condensation product of about 1 to 5 mols of a phenolic compound having the general formula Ram-OH, in which R is an alkyl group having from 4 to 10 carbon atoms, 1: equals 1 to 2, and Ar is an otherwise unsub- X is selected from the class consisting of 0H and a halogen, said condensation product being substantially non-volatile up to about 600 F. and soluble in hydrocarbon oils.

2. A product according to claim 1', wherein the phthalic acid is the acylating agent.

3. A Friedel-Crafts condensation product of one mol of phthalyl chloride and about 1 to 5 mole of diisobutyl phenol, said condensation product being substantially non-volatile up to about 600 F. under fire and steam distillation, being soluble in waxy mineral lubricating ofls, and having waxmodifying properties.

4. A product according to claim 3 being a condensation product of about 1 part by weight of phthalyl chloride to about 3 parts by weight of di-isobutyl phenol.

5. The process which consists in condensing about 1 to 5 mols of a compound containing not more than 20 aliphatic carbon atoms per molecule having the general formula RnAlf-OH, in which R is an alkyl group having 4 to 10 carbon atoms, 11 equals 1 to 2, and Ar is an otherwise unsubstituted aromatic nucleus, with one mol of an acylating agent having the general formula Ar(COX)2, in which Ar is an aromatic nucleus, and X is selected from the class consisting of -OH and a halogen in the presence of a Friedel-Crafts catalyst, and subjecting the condensation product to distillation at low partial pressure to obtain a distillation residue soluble in hydrocarbon oil, substantially non-volatile at temperatures below tabout 600 F. and having wax-modifying properies.

6. The process which consists in condensing about 1 to 5 mols of a compound having the general formula R--ArOH, in which R is an alkyl group having 4 to 10 carbon atoms and Ar is an otherwise unsubstituted aromatic nucleus with one mol of an aromatic dicarboxylic acid acylating agent, in the presence of aluminum chloride as catalyst, hydrolyzing and removing the catalyst and subjecting the condensation product to distillation with fire and steam to about 600 F. to obtain a distillation residue which is soluble in hydrocarbon oils and having wax-modifying propertites.

'7. Process according to claim 6 in which the alkylated phenol used is di-isobutyl phenol.

8. The process of preparing wax modifiers which consists in condensing about 1 to 5 mols of di-isobutyl phenol with one mol of phthalic acid chloride in the presence of aluminum chloride at a temperature between the approximate limits of room temperature and about 400 F., to produce a high molecular weight condensation prod- 7 not, hydrolyzing and removing the aluminum chloride catalyst and subjecting the condensation product to distillation with fire and steam to about 600 F. to obtain the desired product as distillation residue.-

9. Process according to claim 8 carried out in the presence of an inert solvent.

EUGENE LIEBER.

Name Date Number Ellis Apr. 29, 1930 Number Name Date Marshall Aug. 16, 1938 Reift et 9.1.; Feb. 14, 1939 Ogden May 28, 1940 Lieber Dec. 30, 1941 Lemmer May 26, 1942 Mikeska June 30, 1942 Bruson Dec. 8, 1942 Lieber Jan. 5, 1945 FOREIGN PATENTS Country Date Great Britain Feb. 15, 1940 

